Start system time from the same global clocks in every processes after replaying a file

3 files changed, 49 insertions, 34 deletions

diff --git a/src/faketime.c b/src/faketime.c
index 8dfd518..af25edf 100644
--- a/src/faketime.c
+++ b/src/faketime.c
@@ -207,7 +207,14 @@ int main (int argc, char **argv)
     /* init elapsed time ticks to zero */
     ft_shared->ticks = 0;
     ft_shared->file_idx = 0;
-    if (-1 == munmap(ft_shared, (sizeof(uint64_t)))) {
+    ft_shared->start_time.real.tv_sec = 0;
+    ft_shared->start_time.real.tv_nsec = -1;
+    ft_shared->start_time.mon.tv_sec = 0;
+    ft_shared->start_time.mon.tv_nsec = -1;
+    ft_shared->start_time.mon_raw.tv_sec = 0;
+    ft_shared->start_time.mon_raw.tv_nsec = -1;
+
+    if (-1 == munmap(ft_shared, (sizeof(struct ft_shared_s)))) {
       perror("munmap");
       cleanup_shobjs();
       exit(EXIT_FAILURE);
diff --git a/src/faketime_common.h b/src/faketime_common.h
index c8ee3c9..3284c70 100644
--- a/src/faketime_common.h
+++ b/src/faketime_common.h
@@ -24,6 +24,16 @@
 
 #include <stdint.h>
 
+struct system_time_s {
+  /** System time according to CLOCK_REALTIME */
+  struct timespec real;
+  /** System time according to CLOCK_MONOTONIC */
+  struct timespec mon;
+  /** System time according to CLOCK_MONOTONIC_RAW */
+  struct timespec mon_raw;
+};
+
+
 /** Data shared among faketime-spawned processes */
 struct ft_shared_s {
   /**
@@ -32,6 +42,8 @@ struct ft_shared_s {
   uint64_t ticks;
   /** Index of timstamp to be loaded from file */
   uint64_t file_idx;
+  /** System time Faketime started at */
+  struct system_time_s start_time;
 };
 
 #endif
diff --git a/src/libfaketime.c b/src/libfaketime.c
index c76633d..1b5f439 100644
--- a/src/libfaketime.c
+++ b/src/libfaketime.c
@@ -151,22 +151,12 @@ static char ft_spawn_target[1024];
 static long ft_spawn_secs = -1;
 static long ft_spawn_ncalls = -1;
 
-/**
- * Static timespec to store our startup time, followed by a load-time library
- * initialization declaration.
- */
-static struct timespec ftpl_starttime = {0, -1};
 
 /**
  * Static timespec to store our startup time, followed by a load-time library
- * initialization declaration. Saved using CLOCK_MONOTONIC.
- */
-static struct timespec ftpl_starttime_mon = {0, -1};
-/**
- * Static timespec to store our startup time, followed by a load-time library
- * initialization declaration. Saved using CLOCK_MONOTONIC_RAW.
+ * initialization declaration.
  */
-static struct timespec ftpl_starttime_mon_raw = {0, -1};
+static struct system_time_s ftpl_starttime = {{0, -1}, {0, -1}, {0, -1}};
 
 static char user_faked_time_fmt[BUFSIZ] = {0};
 
@@ -315,18 +305,24 @@ static bool load_time(struct timespec *tp)
       /* we are out of timstamps to replay, return to faking time by rules
        * using last timestamp from file as the user provided timestamp */
       timespec_from_saved(&user_faked_time_timespec, &stss[(infile_size / sizeof(stss[0])) - 1 ]);
+
+      if (ft_shared->ticks == 0) {
+	/* we set shared memory to stop using infile */
+	ft_shared->ticks = 1;
 #ifdef __APPLE__
-      ftpl_starttime = *tp;
-      ftpl_starttime_mon = *tp;
-      ftpl_starttime_mon_raw = *tp;
+	ftpl_starttime.real = *tp;
+	ftpl_starttime.mon = *tp;
+	ftpl_starttime.mon_raw = *tp;
 #else
 	real_clock_gettime(CLOCK_REALTIME, &ftpl_starttime.real);
 	real_clock_gettime(CLOCK_MONOTONIC, &ftpl_starttime.mon);
 	real_clock_gettime(CLOCK_MONOTONIC_RAW, &ftpl_starttime.mon_raw);
 #endif
-      if (ft_shared->ticks == 0) {
-	ft_shared->ticks = 1;
+	ft_shared->start_time = ftpl_starttime;
+      } else {
+	ftpl_starttime = ft_shared->start_time;
       }
+
       munmap(stss, infile_size);
       infile_set = false;
     } else {
@@ -687,7 +683,7 @@ static void parse_ft_string(const char *user_faked_time)
 
     user_offset.tv_sec = floor(frac_offset);
     user_offset.tv_nsec = (frac_offset - user_offset.tv_sec) * SEC_TO_nSEC;
-    timespecadd(&ftpl_starttime, &user_offset, &user_faked_time_timespec);
+    timespecadd(&ftpl_starttime.real, &user_offset, &user_faked_time_timespec);
     goto parse_modifiers;
     break;
 
@@ -823,16 +819,16 @@ void __attribute__ ((constructor)) ftpl_init(void)
     /* this is not faked */
     clock_get_time(cclock, &mts);
     mach_port_deallocate(mach_task_self(), cclock);
-    ftpl_starttime.tv_sec = mts.tv_sec;
-    ftpl_starttime.tv_nsec = mts.tv_nsec;
-    ftpl_starttime_mon.tv_sec = mts.tv_sec;
-    ftpl_starttime_mon.tv_nsec = mts.tv_nsec;
-    ftpl_starttime_mon_raw.tv_sec = mts.tv_sec;
-    ftpl_starttime_mon_raw.tv_nsec = mts.tv_nsec;
+    ftpl_starttime.real.tv_sec = mts.tv_sec;
+    ftpl_starttime.real.tv_nsec = mts.tv_nsec;
+    ftpl_starttime.mon.tv_sec = mts.tv_sec;
+    ftpl_starttime.mon.tv_nsec = mts.tv_nsec;
+    ftpl_starttime.mon_raw.tv_sec = mts.tv_sec;
+    ftpl_starttime.mon_raw.tv_nsec = mts.tv_nsec;
 #else
-    (*real_clock_gettime)(CLOCK_REALTIME, &ftpl_starttime);
-    (*real_clock_gettime)(CLOCK_MONOTONIC, &ftpl_starttime_mon);
-    (*real_clock_gettime)(CLOCK_MONOTONIC_RAW, &ftpl_starttime_mon_raw);
+    (*real_clock_gettime)(CLOCK_REALTIME, &ftpl_starttime.real);
+    (*real_clock_gettime)(CLOCK_MONOTONIC, &ftpl_starttime.mon);
+    (*real_clock_gettime)(CLOCK_MONOTONIC_RAW, &ftpl_starttime.mon_raw);
 #endif
 
     /* fake time supplied as environment variable? */
@@ -895,13 +891,13 @@ static pthread_mutex_t time_mutex=PTHREAD_MUTEX_INITIALIZER;
       /* For debugging, output #seconds and #calls */
       switch (clk_id) {
       case CLOCK_REALTIME:
-	timespecsub(tp, &ftpl_starttime, &tmp_ts);
+	timespecsub(tp, &ftpl_starttime.real, &tmp_ts);
 	break;
       case CLOCK_MONOTONIC:
-	timespecsub(tp, &ftpl_starttime_mon, &tmp_ts);
+	timespecsub(tp, &ftpl_starttime.mon, &tmp_ts);
 	break;
       case CLOCK_MONOTONIC_RAW:
-	timespecsub(tp, &ftpl_starttime_mon_raw, &tmp_ts);
+	timespecsub(tp, &ftpl_starttime.mon_raw, &tmp_ts);
 	break;
       default:
 	printf("Invalid clock_id for clock_gettime: %d", clk_id);
@@ -1000,13 +996,13 @@ static pthread_mutex_t time_mutex=PTHREAD_MUTEX_INITIALIZER;
 	struct timespec tdiff, timeadj;
 	switch (clk_id) {
 	case CLOCK_REALTIME:
-	  timespecsub(tp, &ftpl_starttime, &tdiff);
+	  timespecsub(tp, &ftpl_starttime.real, &tdiff);
 	  break;
 	case CLOCK_MONOTONIC:
-	  timespecsub(tp, &ftpl_starttime_mon, &tdiff);
+	  timespecsub(tp, &ftpl_starttime.mon, &tdiff);
 	  break;
 	case CLOCK_MONOTONIC_RAW:
-	  timespecsub(tp, &ftpl_starttime_mon_raw, &tdiff);
+	  timespecsub(tp, &ftpl_starttime.mon_raw, &tdiff);
 	  break;
 	default:
 	  printf("Invalid clock_id for clock_gettime: %d", clk_id);